Among home-use game machines are ones equipped with a camera. Such a game machine can image a user playing a game to display the image of the user on a game screen and can detect the action of the user from the captured image of the user to reflect it in the game. Furthermore, this game machine can also detect the facial expression of the user from an image of the user photographed by the camera and grasp the mental status of the user in the game playing to reflect it in the progression of the game. In addition, it is also possible that plural players each have a controller to operate the game machine, and a game is frequently played by plural persons including family, friends, etc.
Furthermore, in order to detect the degree of nervousness of a user in game playing, the following method is also carried out. Specifically, a sensor to detect the pulse is mounted on the user and the measurement result of the pulse output by the sensor is input to the game machine and reflected in the game.
In Patent Literature 1, a method is described in which a vital sign is measured from temporal change in the density of a captured image of a subject.